Argon vs. Krypton vs. Air-Filled Windows – What’s the Difference?

When choosing new windows, you may have come across terms like argon-filled and krypton-filled glass. But what do these gases actually do, and how do they compare to traditional air-filled windows?

In this guide, we’ll explain the differences between argon, krypton, and air-filled windows so you can choose the best option for your home’s insulation and energy efficiency.

What Is a Gas Fill in Windows?

Modern double-pane and triple-pane windows have a space between the glass panes. This space can be filled with air or an insulating gas like argon or krypton to improve energy efficiency.

Benefits of gas-filled windows include:

Better Insulation: Reduces heat transfer to keep your home comfortable year-round.
Lower Energy Bills: Less reliance on heating and cooling systems.
Reduced Condensation: Prevents moisture buildup between panes.

Comparing Argon, Krypton, and Air Fills

Each type of window fill has different performance characteristics. Here’s a breakdown of how they compare.

Fill Type	Thermal Insulation	Best For	Cost
Air-Filled	Least effective	Budget-friendly, mild climates	Low
Argon-Filled	Better insulation than air	Most homes, standard energy efficiency	Moderate
Krypton-Filled	Highest insulation	Cold climates, triple-pane windows	Higher

1. Air-Filled Windows – The Basic Option

Traditional option used in older double-pane windows.
Allows more heat transfer compared to gas-filled options.
Least expensive but less energy-efficient.

Best for: Homeowners on a budget or in mild climates where insulation isn’t a major concern.

2. Argon-Filled Windows – The Most Popular Choice

Argon is a colorless, odorless, and non-toxic gas.
Provides better insulation than air by reducing heat transfer.
More affordable than krypton, making it the best value for most homes.

Best for: Homes in moderate to cold climates looking for an affordable energy-efficient upgrade.

3. Krypton-Filled Windows – The Premium Choice

Krypton is a denser gas than argon, providing superior insulation.
Works best in triple-pane windows, where space between panes is smaller.
More expensive than argon but offers maximum energy efficiency.

Best for: Extreme climates where extra insulation is needed to prevent heat loss.

Which Gas Fill Is Best for Your Home?

The right choice depends on your home’s climate, budget, and insulation needs.

If you want the most affordable option: Air-filled windows work but have lower energy efficiency.
If you want the best balance of cost and efficiency: Argon-filled windows are ideal for most homes.
If you live in extreme temperatures: Krypton-filled windows offer the highest insulation.

Do Gas-Filled Windows Leak Over Time?

It’s common for gas-filled windows to lose a small percentage of their gas over decades. However, well-made windows with quality seals retain most of their insulating properties for 20+ years.

To ensure maximum longevity: